Car-wheel



G. s. BOSWORTH.

GAR WHEEL.

Patented oct. 2s, 1860 sa@ J. i M

flesse s rnviTEn sTATEs PATENT OFFICE.

GEO. S. BOSVORTH, OF TROY, NEW' YORK.

CAR-WHEEL.

Specification of Letters Patent No. 80,458, dated October 23, 1860.

To all whom t may concern:

Be it known that I, GEORGE S. BoswoRTH, of the city of Troy, in thecounty of Rensselaer and State of lNew York, have invented a new anduseful improvement in such castiron railroad-car wheels as are each castin one piece with a chilled rim and an undivided hub; and I do herebydeclare that the following is a full and eXact description thereof,reference being had to the annexed drawings, making a part of thisspecification, in which- Figures l, 2' and 3 are sections in the planeof the axes, and Figs. et, 5 and 6 elevations, on a reduced scale, ofthree varieties of my improved car-wheel; and Fig. 7 is a fuil sizedradial section of the wheel shown in Figs. l and 4L.

The same letters refer to like parts in all the ligures.

The beneicial result of my invention is the production of a cast-iron,rail-road carwheel, cast in one piece with a chilled rim and anundivided hub connected together by a single plate or disk, which diskis so formed that the wheel, after being cooled down in a commonunheated pit, or in the open air, is left with so little strain oftension or of compression, by the unequal rate of cooling andcontracting of the different parts, that the wheel is, as I firmlybelieve, stronger to resistthe lateral shocks and radial concussions towhich it is subject in use, than any castiron car-wheel of equal sizeand weight previously made in one piece with a chilled rim and anundivided hub, at as cheap a rate.

In the annexed drawings, A is the rim or tread of the wheel; which rimis cast within a chill and in any suitable form for that part.

B is the hub, which is cast upon a core as usual, without being dividedinto segments to allow for shrinkage.

C is the disk or continuous plate which connects the rim to the hub,which plate is strongest to resist lateral shocks when made thickesttoward the hub, as shown in Fig. 7. The plate, C, is undulating in formand has two or more annular waves concentric with the hub and therimwthat is, the plate C has, on each side, two or more annularelevations, d, alternating with annular depressions, c, the annularelevations of one side of the disk being opposite to the annulardepressions of the other side, and concentric with the rim and hub,substantially as represented in the annexed drawings. In Figs. l, L and7 the plate C is shown with two such waves; in Figs. 2 and 5 with three;and in Figs. 3 and 6, with four. I prefer to make the larger wheels withmore waves than the smaller, twovwaves being generally considered bestin wheels of 24: to 30 inches in diameter, three in those of 32 to 34,and four in wheels of 36 `to 40 inches in diame# ter. But I do not limitmyself to making wheels of those sizes with the particular number ofwaves just specified for each, nor to making the two or more waves ofthe plate C of the precise size, nor form shown, nor to uniting the rimand the hub to the par ticular parts of the waves to which they areshown joined in the annexed drawings, but shall vary these ascircumstances shall render desirable. For the distinguishing feature ofmy improved car-wheel cast in one piece is the fact that the chilledrim` is connected with the hubby means ofa single undulating concaveconvex disk or plate having two or more annular waves which areconcentric with the hub and rim, and are not crossed by any such bracesor brackets cast on the side or sides of the plate as will prevent ormaterially interfere with the existence of substantially equal strengthand yielding or springing capability in all radial sections which can betaken through the disk.

I am aware that a car-wheel has been previously cast in one piece with achilled rim and an undivided hub connected together by a single diskwhich has an annular conveXity on each face, but it is obvious that sucha disk will yield or spring much less to the sudden contraction of therim, without straining the metal in the disk, than a concavo-convexplate having two or more annular waves concentric with the hub and rimas shown in the annexed drawings, and I have found by experiment that acar-wheel cast in one piece with the chilled rim and the hub connectedtogether by a disk of the last-named form, is greatly stronger to resistthe shocks and concussions to which car-wheels are subject in use, thana wheel which has the chilled rim connected to the hub by a disk whichsimply has a conveXity on each side concentric with the rim and hub. Toget the necessary amount of yielding capability in the disk of a wheel,when the disk merely has a convexity on each side, the convexities mustproject so far outside of the line of thrust between the rim and hub asto leave the disk too weak.

It is apparent that radial braces or brackets cast on the sides or sideof the undulating disk which connects the rim and hub together, as shownin No. 18767 of United States patents, make some parts of the plate ordisk heavy or thick and others thin at equal distances from the centerof the wheel so as to destroy the equality of strength and elasticitywhich should exist in all parts of the disk at equal distances from theaxis, and prevent the plate from yielding as evenly and as much as itotherwise would under the unequal rate of shrinkage of the various parts,-and it is essential to my improved wheel that the undulating plate, C,thereof, or at least two of the waves of that plate, should be withoutsuch sidebraces or brackets. It is also obvious that such car-wheels asare represented in the annexed drawings are essentially different fromsuch as have Vthe rim and hub connected together by two disks, eachhaving two or more annular waves concentric with the hub and rim; andalso from such as have the hub connected to the rim by means of twoplates extending part way and one the rest, the plates being so formedthat one or each of the faces of the wheel presents two annular wavesconcentric with the hub. For in each of the two cases last named it isnecessary to use a core in casting the plates which connect the rim tothe hub, which use of the core increases the cost of the Wheel, andthose plates are not as free to yield or spring, and are consequentlymore liable to be strained or fractured by the unequal rate ofcontraction of the various parts of the wheel in cooling, than thesingle undulating plate of my improved wheel herein described. It isalso obvious that the plate of this wheel differs from a plate, havingany portion of it between the hub and rim flat in the radial line assuch flat space would form an unyielding arch which would materiallydeteriorate from the yielding'efect so perfectly provided for in mywheel and in which its great strength and Value consist.

What I claim as new and desire to secure by Letters Patent is- The abovedescribed cast-iron car-wheel cast in one piece with the chilled rimconnected to the hub by means of a single undulating concavo convexplate which has two or more annular waves concentric with the hub andrim, substantially as represented in the annexed drawings.

GEO. S. BQSWORTH.

Witnesses:

I. L. BARNEY, A. F. PARK.

